path: context_2025.09.21.20251026+dfsg-1/texmf-dist/tex/context/base/mkxl/font-dsp.lmt
                                                        local l = {
                                                            index     = nofsublookups, -- handy for tracing
                                                            name      = f_lookupname(lookupprefix,"d",lookupid+lookupidoffset),
                                                            derived   = true,          -- handy for tracing
                                                            steps     = d.steps,